We have performed brazing with a TIG torch in the parst. It was in a rather strange application where we had to join Cu to Al.
It appears to be good where the material is a good heat sink (e.g. Cu) and you want to have highly localized heating. Where this is not the case, the TIG torch will tend to melt the base metal, which is not what you want to achieve while brazing.
Another consideration is that the welding arc is too hot to actually melt the brazing filler. It tends to vapourise many brazing fillers. As such, the brazing material must be melted by the heat of the base metal itself, or you need an additional oxy-acetylene torch to do this.
Hope this helps.
Regards
Niekie Jooste